High-efficiency astatination of antibodies using N-iodosuccinimide as the oxidising agent in labelling of N-succinimidyl 3-(trimethylstannyl)benzoate

Monoclonal antibodies C215, reactive with colorectal carcinomas, and MOv18, reactive with most of the ovarian carcinomas, were radiohalogenated with [ At-211]astatine. The radiohalogen was conjugate coupled to antibodies via t he intermediate labelling reagent N-succinimidyl-3-(trimethylstannyl)benzoa te (m-MeATE) in a two-step, single-pot reaction. Optimisation of the labell ing of the reagent was achieved using N-iodosuccinimide, NIS, as the oxidis ing agent. The yields ranged from 69-95% in the labelling of 0.1-1.0 nmole of the m-MeATE precursor. Subsequent conjugation to antibodies resulted in yields of 58+/-7%. In vitro binding to tumour cells showed that the immunor eactivity of both antibodies was retained after astatine labelling. (C) 200 1 Elsevier Science Inc. All rights reserved.